1. Field of the Invention
The present invention relates to a mount for an optical element, and more particularly, to such a mount which can be adjusted to accurately position an optical element in optical apparatus.
2. State of the Prior Art
Optical elements must be very accurately positioned in certain types of apparatus such as apparatus using lasers as a light source. Mounts for the optical elements must be adjustable in order to position the element relative to a laser beam and to compensate for changes in the optical system. The optical elements must also be able to withstand shock and vibration without moving from an adjusted position, and thus, the mounts must include means for locking the optical elements in an adjusted position without inducing distortion or strain in the optical element. One of the main problems in prior-art mounts for optical elements is that the mounts cannot be easily adjusted to a precise position. A further problem with known mounts is that they cannot be locked after adjustment without changing the adjusted position.
In U.S. Pat. No. 4,563,058, there is shown a mount for a dichroic mirror in a transducer for an optical signal recorder. The dichroic mirror includes a hemispherical portion and a planar optical surface. The hemispherical portion of the mirror is received in a hemispherical socket in the mount, and an aperture plate is placed over a portion of the optical surface of the mirror to secure the mirror in the socket. The aperture plate is held in position by four screws. The mirror can be adjusted about orthogonal axes by adjusting the screws holding the aperture plate. A problem with the mount disclosed in this patent is that it is difficult to maintain an adjustment made about one of the axes while an adjustment is being made about the other axis.